Expansion-bolt.



J. R. CONRAD.

EXPANSION BOLT.

APPLIOATION FILED APB. 19, 1912.

1,050,345. Panendaan. 14, 1913.

W'nesseg: Ins/enfer:

sep/v R. Conrad.

" Uiviifnn s'rrtrns PATENT onirica.

JOSEPH R.' CONRAD, OF CHICAGO, ILLINOIS. ASSIGNOR, BY IESNE ASSGNMENTS,TO U: S. EXPANSIONBOLT CO., O' NEW YORK, N. Y., A CORPORATION OF NEW'YORK.

vsXPaNsioN-isoifi.

Specification of Letters-Patent.

Patented Jan. 14, 191

ppiicetion filed April 19, 1912. SerialNo. 691,839. i

.o all whom t may concern i Beit known that I, Josiirii R, CONRAD,

and security than has been heretofore posa citizen ofthe United States,residing at '.(l-'hicag0, in the county1 ot Coolr 'and State ofIllinois,` have invented certain new and useful-Improvements i'nEXpansion-Bolts,

'of which t-hel following,r isi-a specification.

' This invention relates to bolts adaptedto lbe anchored lwithin a solidsubstance, and

particularly snc-h as are designed for attaching fixtures to brick orconcrete walls. lThe principal objects of' the present in ventionaretoconstruct an expansion bolt4 having but va parts, which may beanchored vwithin a wall with greater firmness sible; and toprodnce anexpansion bolt .having shells adapted to be shifted or eX- The expansionbolt. of the present invention comprises essentiallyv three principalpanded away from each other, which operation of shifting or expanding'shall be automaticalt'vv predetermined in such manner as not to"Wea-lrenor iiiipairlthe wall at thepoint. where it is locked therein.

'Other' objects of my invention will appear from a detailed description.of the drawing and'l operation of the parts, as hereinafter set forthand'cl'aimed.

In the drawing, Figure 1 is a 'section of a wall and an expansion bolttl'ierein showing the position of the holt and-shells before expansionhas coinmencedg-Fig-2 isa simi lar View, but shows the 'positionlassumed by the parts of the expansion bolt at the coinnieneenient oftlie expanding operation; Fig. 3 is a similar view showing, however,

the position assui'nedbi-1 the part-s of the expansion bolt after theoperation of ex'- pansion iscompleted; and Fig. is a View similar toFig. 3 showingr 'the expansion bolt in elevation. l

. parts,"'viz., a pair .of segmental symn'retrical shells 5,.anexpanding;1 .in'eiiiber G adapted to tr'Yello-ngitinJ-inally therein,and a bolt 7, upon which in snd e.\'pandiii(I member lis threaded,andfby whichxtlie 'saiu longitu dinal n ioveineiit is impart-edthereto.' VThe I'shells illustrated in the drawing` are each forined onthe interior with two lfaces at right angles to each other and inclined=from the inner to the outer .end thereof, and

are adapted-to present contactl faces for an v etpaiider in the form ofa square nut which hears each of its sides against one of the r.lliisforni of construction is described at length and claimed in my pendingapplication, Serial No. (322,109, filed April i9, ]911. lt should heunderstood that the 55 said inclined interior faces of the shells`present invention is equallyapljilicable in conil'iinatnin with anyAexpanding` nicniber and shells (littering materially inferossvsection.

At .the inner end. -of each voli' the shells,

there is foi-ined a. web 8^liaving a portion thereoteut away to providein effect a pocket 9. The arrangement of each of the webs Sand cut-awayportions therein. is such that, when the shellsl are placed together inposition, a complete closure is provided at-.the inner end thereof withzthe tapered pocket formed in substantiallyY the axial line of theshells. The pocket. at the sidevhich faces the interior of the shells isof a suitable diameter to receive the inner er acting end of thebolt 7,andtapers inwardly in such a manner that 'upon ad vancenient of the bolttherein, the shells will of necessity be forcedapartat their inner endsas bv a wedge-action;

The exterior of theshells is'provided Wit-h i i a number ofspirallv-fornied threads 10 u thereon adapted to effect a tightl andsecure hold against-'the wall within which the exvpansion -bolt isanchored. Locking means when bent inwardly t-o embrace neck por'- tion12 upon the other of said shells. A

flange 13 formed at the outer end of one of the shells Serves as a capVto cover'the edges of the hole within which the expansion' bolt issecured, as well vas to predetermine its proper longitudinal positiontherein. Y

In putting' into use the-expansion bolt `of the present invention. thesteps and operations"in\'ol\ed are substantially as follows: Theexpansion bolt.. is A'first assembled hy in# serting` the bolt throughthe flanged' end of one ofl the 'shells and threadingr the nut. thereon.The other shell is then broughtinto proper registering position and -islocked with respect to its oo-acting shell by means of the bendahle lugsorined at' the. outer end'thereof. ,With the mit in eosiv which I amaware.

tion at the extreme inner end of the shells to permit of their lyingclose to one another the expansion bolt is then inserted into a hole ofproper size which has been formed in ,the wall or ceilinowhere it is tobe anchored. Rotation ot-J the holt is then commenced which will causeits acting end, to seat within the tapered pocket on the interior of theshells to apply a wedge pressure thereto. Inasmuch as the outer ends ofthe shells are held closely together by'means of the embrace of; thelocking lugs, movement of the nut in that direction against the inclinedfaces of the shells cannot readily take place, with the result that theacting end of the bolt will be advanced farthen into the tapered pocketat the inner endvof the shells; this movement causes the `shells attheir inner end to expand and bite into thematerial within which theexpansion bolt is being anchored. It is'obvious after the acting endofthe bolt has advanced a certain distance and has expanded the inner'ends of the shells against a constantly increasing pressure that furtherinward movement of the boltmust cease, and that resistance tothe travelof the nut being now less than that otl'ered to thelongitudinal movementof the bolt, the nut will be caused to travel out ward. y (See Fig. 2).During the longitudinal travel of the nu't to the position indicated inFig. 3 the inner ends of the shells will be constantly maintained inexpanded position, for the reason that/tire bolt coi1-` tinues to exertan end thrust against the inner end of the tapered pocket, therebyeffectually preventingr any tendency of the shells to collapse at theirinner ends. The limit of expansion will obviously be reached when thenut has advanced to the outer end of the shells, as shown in Fig. 3,which point can only be reachedafter sufficient expanding pressure'hasbeen communicated to the outer end -of the shells to cause the lockinglugs to release their holdV to permit of the shells shifting away fromeach other.

By the construction of an expansion bolt which operates substantially inthe manner just described, I am enabledv to secure a hol-d within thehole more tight and secure than is possible with any other form of boltof In order that. the outer edges of the hole may not be weakened ormutilated, beingobviously the partmost susceptibleto cruml'ilingr andchipping, it is eS- sential that the operation of expansion should takeplace initially at the inner end yof the holo. This I have accomplishedby means of the acting end ol' the bolt which .is made to exert a wedgeaction` within the ta )cred pocket formed at the interior of the stells, lt is not enough, however, that the expansion should be commencedat the inner end of the shells for the reason that greatest efticiencywill result only when the whole ex- 4'other so as to facilitate theirinsertion withterior surface of the shells is made to grip and engagethe interior of the hole within which the expansion bolt is anchored,thus guarding against possible slipping or slid 111g movement of theshells Within the hole.

As has just been explained, the' shells of the present invention areexpanded` at their outer ends to attain the greatest locking efficiency,only after the inner ends thereof have first been firmly embeddedagainst the sides of the hole. The successful operation ot' causing theexpansionto take place in substantially the manner just described isassured throughthe agency of the locking lugs at the outer ends of theshells which by retarding the advancement of the nut causes the bolt toadvance into the tapered pocket to expand first the inner ends of theshells.-

The pocket, as shown `in the drawing, is substantially in the form of aparabolic conoid and whenso shaped is admirablyI adapted for thepurposes of this invention. lt will be noted that the acting end of thebolt must engage first with that portion .of the pocket where the sidestaper only slightly, thereby conducing to the ready eX- pansion of theshells at the inne;` end. As the acting end of the bolt advances intothepocket, however, the radius of the curve thereof decreases, with theresult that increasing pressure is gradually brought upon the inner endot the bolt to prevent its further ingress into the pocket. It iscustomar to form such bolts with their ends bevele as s hown in thedrawing, so that the thrust of the bolt upon the faces of the pocket isnot that ot' an edge so sharp as to mutilate either of the engagingparts, or to produce an undesirable amount of friction:

The lugs formed upon one of the shells adapted to embrace the otherthereof for the purpose of effecting a releasable union therebetweenoperates not only in conjunction with the engaging action of the bolt inthe tapered pocket at the inner end .of the shells to produce the novelexpanding operation already explained, but serves as Well to lock theshells together in proper relation to each in the wall. It will be notedalso that the neck portion of the shell which is embracedl bv thelocking lugs is so formed as to pre-t vvent longitudinal movement` ofone shellv with respect to the other, when embraced by the locking lugs.This is of particular importance in view of the fact that withoutltheprovision of means to prevent' longi- ,tudinal movement of one shellwith respect place 12'5 to the other expansion could not take at theinner end of the shells through the wedge action exerted by the actingend of the bolt.

Q' It will be observed that, although the expansion bolt of my inventionis construct- Led-:so as-to expandupon a nove Aiprifn" i ple operation,and topresenticer a1 n .other `g-.to-increase expense orcioniplic'ation.

fpansion .of the shells may-be. ,of the ordinary standard pattern. -T'hemeans'also by @which the shells are relea'sa'bly held to- ,fgether, aswell as the ca pfpiece'ui'ised, to predetermine .t-helongitudinal.position of the .stiell'sfwitliinjthe walls, and :to conceal the hfoletherein, are formedintegral with the shells, thus' minimizing' the"numherof. pa'rts I ingl shells, each formed on its interior with adaptedwhen rotated to advance its inner= longitudinally inclined faces,an,.exp ansion member within said shells 'adapted'. when tidvancedagainst said inclinednfaesto force said shells apart, awebformationattlie 1nner end of each of said Ashells having' a cutaway taperedportion'therein, a bolt in engagement with said expanslon member actingrend against'the tapered faces of said cut-away portion to forcethe innerenfls of said shells apart, and means for preventing; initialexpansionof said shells at the outer ends thereof, siibstantiall';7 asdescribed. Y

2. In an expansion bolt, a pair of co-act.v ing'shells, each formed onits interior withlongitudinally inclined faces, an expansion memberwithin said shells adapted when advanced against said inclined faces toforce Said shells apart, a web formation at the inner end of each ofsaid .shells-.having a cut-away tapered portion therein, a bolt inengagement with' said expansion member adapted when rotated to advanceits inner acting end against the tapered faces of said cut-away portionto force the inner ends of said shells apart, and means for preventinginitial expansion of said shells at the outer ends'thercof, said meanscomprisingr a'pair of bendable lugs formed atthe outer end of one ofsaid shells adapted to yieldingly embrace a. portion of the other ofsaid shells,

Substantially as described.

3. In an expansion bolt, a pair of co-acting shells, each formed on itsinterior with longitudinally inclined faces, an expansion member withinsaid shells adapted wheny featilres ofradvanta'ge and iniportance,.thei'e l1s not provided any additional part-s-,tend-` enut and boltemployed to'eflect theexf other pocket substantially the' cessary,toft-he operation `of the -ex'p .nsionaeting'i'end against thetaperediwalls ofsaid vpocket td force the inner 'ends of saidshelilsapart,su`bstantially'as described.

4. ln anv expansion bolt, appair 'of comet- .in'g shells, each V formedonits interior with.

longitudinallyinclined faces, an'fexpansion memberwithin'said'shells-adapted when adifaneed'against said inclined faces toforce said shells apart, a web portion fatthe inner cndof each of 'saidshells having a ciit-an-'a 'yY tapered portionA therein constitutingwhen brought into registering po tion with .each forinof a .m 'intA"ivitli parabolic conoid, a b ol't in en,i;a",

said fexpanslon meinberfadapt'ed.when -rotated to -adi'fance'itsactingiendzlagainst the tapered .portionof said pochette' force thetially as described.

- 5. 'ln an expans Vinner ends of saii'lsliellsgapart, and means "for",preventingrV initial `expansi.o`n". ots vshell-s at the outer endsthereof' substan- '85 ing shells, each formed on its interior withlongitudinally inclined faces, an expansion member wil liin said shellsadapted. n'lien ad-l vanced Vagainst .said inclined faces to force saidshells apart, a we.) adjacent the inner end of each of said shells, thefacing walls of of said webs tapering toward the inner ends thereof, abolt in engagement with said expansion member adapted when rctated toadvance its inner acting end lie-- tween the tapering facing walls ofsaid webs to force the inner ends of said shells apart, means forretardii'ig the advancement of said expansion member' toward the outerends of said shells, said means serving also to maintain a fixedlongitudinal -relationbetween said shells, substantial ly as described.

6. In an expansion bolt, a pair nico-actingshells, each formed on itsvinterioiwith longitudinallyinclined faccs,-an expansion member withinsaid shells adapted when ad- `vanccd against said inclined faces toforce'- said shells apart, a web adjacent. the inner end of each of saidshells, the facing. walls of each of said webs taperingr toward the inner ends thereof, a. bolt in engagement with said expansion member,adapted when rotated to advance its inner acting end between saidtapering faces -to force said inner ends of said shells apart, and meansfor retarding the advancement of said. expansion member within saidshells to-z ward tlie outer ends thereof comprising a.. pair of lugsintegrally torincilja-'illi one -of said shells and adapted toieldinfrlv ern f Abrace i'iie vother thereof, said iiicans serving alsoto maintain a (ixcfl loiigiti-idina-l relation between lsaid shells,substantially as described..

7.. In an expansion bolt, a pair ofen-acting shells, each formed on itsinterior with longitiidii'ially inclined facesLan expansionmeinbeirwithin said shells adapted when advanced against said inclinedfaces to force said shellsapart, a web adjacent the inner' end of eachof said shells, the facing walls of each of said Webs tapering towardlthe inn'er ends thereof, a bolt/.in engagement with said expansionmember, adapted when rotated to advance its inner acting end be-- tweensaid tapering -facesto force the inner ends of said shells apart, meansfor retarding the initial advancement of said'expansion member withinsaid shells toward theouter ends thereof comprising alpair of lugsintegrally formed with one ofsaid shells, and adapted to yieldinglyembrace the other thereof, said means serving also to maintain a fixedlongitudinal relation between said shells, and a flange member-securedto the outer end of one of said shells adapted to rest against theexterior surfaceof the an-v said`shells apart,. means for advancing said30 Y expansion member agalnst sald inclined faces, means for expandingthe inner ends of' said shells, and means for retarding the ad#vancement of said expansion member to permit initial expansion at theinner ends o said shells, substantially Aas described.

9. In an expanslon bolt,.a plurality of segments adapted to be expandedwithin a A substance, means for expanding said seg` ments at their innerends, means forex- 40 panding said segments-at their outer ends, andmeans for retarding the expansion of said segments at theirouter ends topermit initial expansion at the inner ends thereof, substantially asdescribed. l y

JOSEPH R. CONRAD.A

Witnesses: l

WALTER S. ROTH, EPHRAIM BANNING.

